\(x^4-x^2-56\)

\(=x^4-8x^2+7x^2-56\)

\(=x^2\left(x^2-8\right)+7\left(x^2-8\right)\)

\(=\left(x^2-8\right)\left(x^2+7\right)\)

\(x^4-x^2-56=x^4+7x^2-8x^2-56=x^2\left(x^2+7\right)-8\left(x^2+7\right)\)

\(=\left(x^2+7\right)\left(x^2-8\right)\)

\(x^4-x^2-56\)

\(=x^4+7x^2-8x^2-56\)

\(=x^2\left(x^2+7\right)-8\left(x^2\:+7\right)\)

\(=\left(x^2+7\right)\left(x^2-8\right)\)

~ Rất vui vì giúp đc bn ~

4x²-4x+1=(2x)²-2.2x+1²=(2x-1)²

\(4x^2-4x+1\)\(=\) \((2x^2)-2.2x.1+1^2\)

\(=\left(2x-1\right)^2\)

Học tốt!

 4x^4 - 32x^2 +1 = 4x^4 + 4x^2 +1 - 36x^2 = (2x^2 + 1)^2 - 36x^2 = (2x^2 - 6x + 1)(2x^2 + 6x + 1) 

4 x⁴ - 32 x² + 1 

= ( 2 x² )² - 2 . 2x². 8 + 64 - 63 

= ( 2 x² - 8 )² - 63 

= ( 2x² - 8 + √63 ) ( 2x² - 8 - √63 )

Xong

\(x^2-4x+4-y^2\)

\(=\left(x-2\right)^2-y^2\)

\(=\left(x-2-y\right)\left(x-2+y\right)\)

(x - 2)² - y² = (x - 2 - y)(x - 2 + y)

\(x^2-4x-y^2+4=\left(x-2\right)^2-y^2=\left(x-y-2\right)\left(x+y-2\right)\)

\(x^2-4x+4-y^2\)

\(=\left(x-2\right)^2-y^2\)

\(=\left(x-2-y\right)\left(x-2+y\right)\)

(x - 2)² - y² = (x - 2 - y)(x - 2 + y)

\(=\left(x-2\right)^2-y^2=\left(x-y-2\right)\left(x+y-2\right)\)

=4x²-y²+8y-16

=4x²-(y² - 8y+16)

=4x²-(y-4)²

=(2x+y-4)(2x-y+4)

   4x²-y²+8(y-2)

=4x²-y²+8.y-8.2

=4x²-y²+8y-16